FIG. 1 and FIG. 2 are schematic sketches of the female reproductive system of many placental mammals. FIG. 1 illustrates the normal human and higher primate anatomy with simplex uterus, and FIG. 2 illustrates schematically the bicornuate or bipartite uterus as found in many other placental mammals including dogs, cats, and pigs, and which may occasionally be found as a birth defect in humans. Some other mammals, including rodents, may have two separate uteri, each with a separate cervix leading into their vagina.
The female reproductive system 100 of higher primates, or that of many other mammals 102, has a uterine body 104, 106, and a pair of fallopian tubes, including a right tube 108 and a left tube 110; in mammals having bicornuate or bipartite uteri the uterine body has a right 105 and left 107 uterine horn—normal pregnancies in these mammals often occur within the horns 105, 107. Each tube extends from the uterine body and ends in a multiplicity of fimbriae, the fimbriae being projections that surround an ovary, fimbriae 116 of the right tube surrounding a right ovary 112 and fimbriae 118 of the left tube surrounding a left ovary 114. When an oocyte is released by an ovary, the fimbriae 116, 118 capture the oocyte and direct that oocyte into a lumen, or passageway through, the associated fallopian tube 108, 110, and into the associated uterine horn or body. A cervix 120 demarcates a distal end of the uterus and separates the uterus 104, 106 from the vagina 122. (The vagina is not shown in FIG. 2.)
The vagina 122 has a passageway or lumen 124 extending from outside the body to the cervix, and the uterus has a passageway or lumen 126 extending from the cervix to each fallopian tube 108, 110. Each fallopian tube also has a lumen, the right tube having right fallopian lumen 128 and left tube having left fallopian lumen 130.
In order to prevent pregnancy, the fallopian tube lumens 128, 130, may be obstructed. A common surgical sterilization procedure involves cutting the tubes and tying them off, such that their lumen is no longer contiguous. In an earlier U.S. Pat. No. 6,485,486, the present inventor has suggested applying microwave energy to an antenna inserted into the fallopian tube lumen, the surrounding tissue being heated by the microwave energy and damaging a lining of the tube. In another application, PCT/US2011/040722, the present inventor has suggested heating a particle suspension located within the fallopian tube lumen to damage a lining of the tube sufficiently that the tube heals with scar tissue formation. In either method, the scar tissue blocks the tube, leaving the lumen no longer contiguous and preventing oocytes from reaching the uterus.
It is undesirable to obstruct the uterine lumen because this is the primary passageway for menstrual discharge.